Conventionally, a seatbelt retractor for the front seat of a vehicle is housed inside a center pillar from an opening portion formed in a lower portion of an inner panel of the center pillar, and thereby mounted to a vehicle body.
For instance, as disclosed in Japanese Laid-open Patent Publication No. 2006-315572 (paragraphs 0015-0034, FIG. 1-FIG. 7), a fastening piece protruding upward is provided at the center position of the lower edge portion of an opening portion formed in the lower portion of an inner panel of a center pillar. Additionally, a screw hole is formed in the vicinity of the center position in the upper edge portion of this opening portion. The lower end portion of a base plate of the seatbelt retractor is fastened to the upper end portion of the fastening piece with a bolt and nut. The upper end portion of this base plate is fastened with a bolt and nut at the screw hole formed in the center position in the upper edge portion of the opening portion through a mounting plate member having a crank shape in cross section and formed so as to overhang the outside of the vehicle.